Track frame for tractors



Aug. 12, 1930. o. L. GILLILAND TRACK FRAME FOR TRACTORS Filed Sept. 5, 1925 3 Sheets-Sheet 2 Mm w III/II 0 m wmw mun NAN Aug. 12, 1930, o. L. Gi'LLlLAND TRACK FRAME FOR TRACTORS Filed Sept. 5, 1925 5 Sheets-Sheet 3 Patented Aug. 12,71 930.

U TED? S ATES PATENT/OFFICE j 033A L. GILLILAND; or MINNEAPOLIS; immn'nso'rn, ASSIGNOB TOGILLILAND' oomrANY, OF MINNEAPQLIS, MII'NNEHSOT A, A CORPORATION or DELAWARE TRACKFRAME FOR TRAGTORS Application filed September 1 Tasmaniantease a tI'adtOIf or trucli and particularly, to ,a tread chain frame adapted to be used on such tractor or truck As is well known, endless tracks for tractors are now widely used for heavy duty. 'Itiis desirable in such an endless track structure to have a frame for the track whichisfpivotally mounted about a transverse pivot so. that it may swing in a verticalplane and it is desirable to have this pivot at the rear o'f the center ofithe track frame. It is also desirable to have a track frame for the endless tread chain or track having, means for. taking up the slack in the chain for absorbing the shock as the track sections engage the ground and for giving leeway or resilient movement to compensate for the various stresses 1 and strains in the chain as. it travels aboutthe It is the object of this inventionto provide a novel and improved track frame foran endless treadchain, incorporating the saidfdesirable features and other features' therein. t

i The objectsand advantages of theflinven tion will be" more fully setQf irthin lowing description made; 1n; connection with the accompanying drawings }in which like reference charactersrefer. to the same, parts throughout the diiferentyiews, andfin which, Fig. 1 is a V16W. in side elevation of." the track frame showing a portionfoftheendless tread chain in position thereom findicating some of the lines; I 7 v v w in Fig; 2 is a view, for'the most part in's de elevation of said track frame withother po tions shown in Vertical sectionand also show ing a driving sprocket for the tread chain, a portion of the tread chainbeing shown n dotted lines;: 1 3 Fig. 3 is avertical sectiontaken;on' the lin e'3-3Yof Fig; 2, as.indicatedfbyfithe ar rows;

tread chain rollers] in dOtted mg; 3418" a Vertical 0'1 the linkl ofFig. 2,-asindicatedby the arrows; Fig. 5 1S2; horizontal sect ionta'ken on the line 5.5 of

rows; e p, Fig. 6 is a partialtop plan viewi of Fig.2; if r qst p r i top Pl n V w of thetrack frame, certain of the parts being and certain parts shown in vertical section of a'truck-shown in dotted lines; v Fig.8 1s averticalsection taken on the line and i Fig. aim plan View illustrating a par (3f links for a type of tread chain that may be used. 7 i

1 Referring to the drawings, the] device com prises a track frame designated generally as A having disposed thereabout anendle'ss tread chain or track designated as B. The

track frame-A comprises a rear section/A tially" a 1 semicircular or semi-cylindricalfor 8+8. of igl 2, as indicated by the arrows;

mation to the top thereof. The surfaces 11 1 have an outwardly extending flange 12 is at their inner sides which extends inwardly of said-sectionas the web 13; i The Web 13is provided with: a plurality of openings 14 of dif ferent shapes, asfshown in Figs. land 2 and extends to a pair of spacedrear hubs15 and toan ijntermediate hub 16, said wehibeing strengthenedby ribs 15 extending radially from the, hubs 15, and other ribsl6 fle'xtend radially-from the hub 16. The top of the casing forming the main portion of section "A? is downwardly curved at its top having the top surfaces 17 disposed in longitudinal alinement with the: surfaces l 11. Said casing also hasfa heavy. central web 18 thickened at" its upper edge extending from the hubs 16 to its front end from which transverse ribs, ex.-

tend-to the side portions 10,".a bottomf web 18 extendingbetweenside P0rtions 10. The

central rib 18 provided withseverali'openings l8. Thetop portion of therear section above thecenters of hubs lQhasitssurfaCeS 112 offset: downwardly andf'blocks 119 are boltedtliereto'each having-the forwardly projectingtongue 19?. The'to'ngue '19 is embraced in aslot formed-central1y of a rearzwardly projecting block20 which is overlapped by andis bolted to the rearend ofa comparatively thin resilient plate 21 which tion o section A and aline at their outer surfaces and at their top edges with the the plates 21.

is curved inwardly toward surface 17 and is V secured'at its front end to the upper portion ly in the same horizontal planes as the rear end of section A and the rear section of said plate, respectively. The section A has an outwardly extending flange 22 at each side extending around its bottom portion outwardly of the'track surface 11 and around its circular rear end portion. This flange terminates in a vertical line passing through the center of hubs 15, and side'flanges 23 of angle shape, as shown in Fig. 4, are bolted to the sides of said sectionhaving downwardlyextendin'g lugs 23at each end for this purpose, which lates 23 form flanges at the top porflanges 22 at the rear of said section and a similar flange on the front-section A. A track plate 24 of'comparatively thin material, preferably steel, abuts the rear end. of each plate 21 and extends around the rear of section A being superposed on the surface 11 and along the bottom of section A, said plate 24 terminating in an edge 24" inclined to the longitudinal axis of the frame A shown in Fig. 5. Headed screws 30 extend vertically from bosses on top of hubs 16 beneath The front portion ofsection A terminates in atransverseflange 25 having spaced finished surfaces extending vertically at its bottom then horizontally at its intermediate portion and again vertically at its rear. The forward section A has a similar flange 26 at its rear side also having finished surfaces adapted 'to fit against the surfaces of flan e 25; The sections A and A. are adapte movement and for this bolt 27 is threaded intothe flange 25 and abuts against the flange 26, said bolt preferably belng provided with a jamb nut. Said flanges 25 and 26, at their horizontal portion's, are provided with elongated slots through which pass the headed and nutted bolts28 adapted to holdsaid sections in their relatively adjustedpositions. Said sections are also held in theiradjusted positions by the headed and nutted bolts 29, it being possible to insertshims'between the vertical surpurpose, a headed faces of flanges25 and 26 when the sections are so adjusted. The forward section A comprises the, outer flanges 22 alining with the flanges 22 on section A andalining at their upper portions with plates 23. Said section also has the inner flanges 12? flat surfaces 11" which, at the bottom portion of sectionA aline horizontally with the for relative longitudinal extend inwardlyas the.webs13,said webs A being ali ed plurality of holes 14? there-Q surfaces 11 but are ofiset inwardly at 11 and extend in such offset relation to the upper end of section A. A comparatively thin track plate 24 is disposed on the surface 11' at the bottom of section A and at its rear end, this plate 24 has an inclined edge 24 closely ad]acent and parallel to the edge 24 of the plate 24, the outer surfaces of plates 24 and 24 adjacent the edges 24 and 24 beextends around the ing flush. The plate 24" d semi-circular front end of section A alines vertically and horizontally at its upper end with the forward end of plate 21. A

resilient cushion 31 ofrubber or similar material is disposed between the late 24" and the inwardly oifset portion osurface 11, as shown in Fi 2. It may be here stated thatthe outer anges 22 on section A are made as separate pieces and bolted to the casting forming the central part of said section, as shown in Fig. 3. Securing bolts 32 extend through the inner flanges 12 and through the resilient cushion 31. The plates or flanges 22are provided with elongated longitudinally extending slots 22" which the bolts '32 pass so that after the sectionsi l. and A are separatedthe plates or flanges 22 ment, with flanges 22 and plates 23.

bottom rear portion'or section A and the forward rear portion of section A at their portions 10, are divided along lines. parallel the flanges 23 at the top ofsaid sections.

Said flanges at thetop'are substantial] parallel,bu't, as shown in Fig. 7, said auges at the bottom extend outwardly gradually from pointsbelow the centers of the semicircular' ends of sections A and A to a point substantially midwayof said centers.

The frame A is su ported about a trunnion formed on "an ax e35 which is the rear wheel axle ofthe truck to which the device is applied;- A drivin in the hubs '15, which ubs are closed at'their ends by theplates 15' bolted thereto, and a drivin sprocket 37 is secured to the shaft 36, sai' sprocket having rearwardly extending arms in the outer ends of which are journaled I the rollers '38.

7 links ivotally connected'toformthe treadchain; Said links haveb'earing rollers 39 journaled therein which are spaced and adapted to engage the outer sides of the plates 24, 2'4 and 21, as shown inFig. Attention is called through i may be movedagain into enga lgishaft 36is journaled p The rollers 38 are adapltedjto engage in central openings 39' in ta 3 which links are 12 front portions thereof, as shown in have converging inclined surfaces 39' at one to the fact that the links 39, particularly the Fig. 9,

end. The tread chain. B specifically forms no part of the presentinvention, the same be ingidisclosed and claimed in applicants copending application executed July 13th. 1925, Serial Number 54,696, filed September 5, 1925. The shaft36 has secured toitsinner side a driving sprocket 40 adapted to 1 be driven by a smaller sprocket 41 secured to the driving shaft of the truck or tractor by means'of a chain 42. Portions of the truck frame are shown in dotted lines in Fig. I as 43 and a radius rodz l lembraclng the hub 16 at one end and a'dapted to be universally con nected by the bolt 44; to the truck frame at itsother nd is also .ShOwn.

In operation, the frame; A and its tread chainBare'applied tothe axle ofa truck or tractor, as shown in Fig. 7, While the device can be appliedto any suitabletruck or tractor, in the embodiment ofthe invention i The sprocket lO is then in position to be driven by the. standard sprocl'zet 'flfalready on the truck. The sprocket {lOdrives shaft 36 which, in turn,;revolves the driving sprocket37 which engages the links of the tread chain B. The weight of the frame A and'the greater part of the weight of the truck and load ison'the part of'chai'n Bin contact with the groundqandthe re -action the tractor forwardly in a manner Qwell known for an 'endlesstrack structure. The tread chain 13 isv placed in connected position on the frame A and the latter canlthen be adjusted by moving sections A? and A longitudinally to properly tension the chain on the track. As stated, this adjustmentis made by the bolts 27' and sectionA is moved away from section'A the desired amount.

v In the movement the inclinededges at the" bottom part of the section and the inclined,

edges on the track plate-24 and 24 move away from each other longitudinally of theframe. The space between theseparts may,

if'desired, be filled-by a plate of proper being inserted between the vertical portion of flanges 25 and 26.. As stated, after the I sections A and A are adju'stedQplates or flanges 22 can be. moved rearwarfdlyso as to engage the front edges of the plates 22 and 23, bolts 32 then being tightened. The structureis now in positionJtobe -operated '1." and the sections A and A canbe adjusted at: intervals to, keep the chain properly tensionedafter the same has become loose I through wear. In practice, the chain istensioned after about every thousand miles of travel. The top runof the chain rests'on the resilient bar; or plate 21 and this plate will be flexed more or less-by the weight of the chain. The chain can thus sag to a certain degree and keepthe slack taken up and. at'

the same time, it is supported. The limit of bending or flexing of plate 21, can be adjusted ,by adjustment of screws 30, said screws beingcontacted by plates 21. It will be noted that plates, 21 are rigidly fastened so i i at tlieirfront ends butareslidably secured at their rear endsso that the blocks 20 will I slide back and forth relatively to blocks19,

the same being kept in proper relation by tongues 19. The links are guided and held in proper lateral position at the ends andtop,

of the track by the plates or flanges 23, 22 and 22. Theftruck or. vehicle is ste-ered by the front wheels and when'the front wheels areturned laterally there is a tendency to] swing the track frame laterally. Owing to the fact that thetrack, that is, the distance betweenfianges 22 and 22 at the bottom of the tractor is wider than the distance between I the outer edges of wheels 39, the frame can move somewhat laterally across the links at the bottom which are on the ground. This earth the rear end of the frame will sink of the driven chain moves the frame A and downwardly into the earth, owing tothe j drivingbeingat the rear end,,so that'the frame will be in" an upwardly inclined position with the tread portionsof the links disposed, on an upwardly inclined plane, as

shown in dotted lines in Fig. 1. 'When the i links'thus sink into the ground and the chain ground is, of course, stati onary and. if, the

frame sinks sufliciently' the wheels 39 will brought into the ground and thec surfaces will als'oassist in the tractive force exerted. When the tractor isthus'operating in soft earth the -track, as stated, is inclined up hill andthetractor continues in motion no matterhow deeply the same sinks. [With such" endless tread tractors therev is a' jar or shock, g ven tothe framewhenthe; links come into contactgwith the ground. Inthe present;

structure this'shock relieved and absorbed by the resilient cushions 31' inserted beneath thetrack plates-24:.

' Thetrack frame andtreadjchain canalso :be used for; trailer purposes. The engage j .ment ofthelinks 'with'the ground causes the chain toroll aroundthe frame on its roller bearings, thus forming in effect an elongated wheel. The tractor effect will be applied at the axle hub.

' From the above description'it is seen the a plicant has provided a simple and very e 'cient'tractorstructure. The frame is supported for very effective movement and the treadchain is moved in an eflicient and effective manner, the same being kept properly tensioned and the shock and vibration there-- of being substantially eliminated. V The structure is particularly adapted for operating on soft ground. The device has been amply demonstrated in severe trials-and actual practice and the tractor has been moved through soft ground where operations would Ordinarilybe considered impossible. The rugged trials given the structure and practice have shown the same to be very substannovel parts and combinations of parts dis closed and defined in the appended claims;

What is claimed is:

1. A track frame for an endless tread chain {having a track plate extending thereabout with which the bearing members of said tread'chain engage, a portion of said track plate atthe top of said track frame being concavely curved respective to said frame and resilient.

r 2. A track framefor an endless tread chain tractor comprising an elongated oblong structure ha'vinglaterally spaced tracks for ans #14 ally without skidding as th'eframe is steered. '4. A track frame "for-an endless'tread chain, comprising an elongated substantially oblong structure having laterally spaced tracks ,for said'chain extending around the same, flanges atthe outer sides of said tracks, said tracks being of greater A width at the bottom than at the top of said structhre and said flangesbeing' spaced farther apart at the bottom thana t the top, of the said tracks, wherebylateral movement ofthetread chain will be permitted in the lower portion of the track frame to permit theirame to be steered withoutthe lower run of the chain skidding.

5. A device of the class described comprlsing an oblong frame adaptedto form a track for an endless tread chain, said frame having an inwardly and concavely curvedtop portion, was track formingplat'secnr'd to said frame and spaced from said'pertion between its ends, said trackforming plate being somewhat resilient and comprisingasection fixedly secured'to said frame at one endand slid ably engaging said frame at its otherend.

[6. A track frame for an endless tread chain, comprising laterally spaced elongated tracks with substantially semi circular ends, said tracks having longitudinally spaced top portions at their upper sides, and resilient track plates each rigidly secured atone end a to one of said top portions of one of said tracks, extending between the spaced ends thereof and resting at its other end on the other top portion ofits respective trackand being downwardly curved between the 'top portions. V

In testimony whereof I allix my signature ORRA L. GILLILAND,

said chain, each having a substantially horizontal bottom portion, substantially circular end portions, and a, resilient downwardly p curved top portionadapted automatically to moveunder the weight of said chain and take up the slack thereof and means for ad- I justably limiting the downward movement of said resilient downwardly curved top portion,

3. A track frame for an endless tread chain tractor comprising an elongated oblong structure having laterally spaced tracks for said chain, each having a substantially horizon tal bottom portion, substantially circular end portions, a resilient top portion. adapted automatically to move under the weight of said chain and take up the slack thereof, and

vertical flanges extending outwardly from the sides of said tracks, said tracksbeing wider at their bottoms thanat their'tops and said vertical flanges being spaced a greater 'dls'tance apitrt at the bottom thanat the top o'fi s'aid frame to permit sliding movement of a thelinksof thelower'run ofthechainlater- 

